As described in U.S. Pat. No. 5,361,803 for example, a valve having a junction type housing formed by connecting a plurality of housing members to one another is conventionally known. In this conventional valve, the housing is divided into upper and lower two housing members from a division surface including an axis of a valve hole. These housing members are connected to each other, and joint surfaces thereof are integrally connected to each other by adhesion or welding.
In such a junction type housing, when the two housing members are to be connected to each other, they are prone to be deviated from each other and thus, it is necessary to hold both the housing member so that they are not deviated from each other in some way. If both the housing members are deviated in position and connected to each other, when the valve hole is formed thereafter, a working margin is increased by the deviated amount, and labor and time required for forming the valve hole are increased and thus, the costs are increased. Since the conventional valve does not have means to position the housing members at the time of connection thereof, it is difficult to precisely connect the housing members to each other.
On the other hand, Japanese Patent Application Laid-open No. 2003-65453 discloses a technique for soldering the two housing members in a state in which they are positioned by fitting a convex portion and a concave portion to each other. However, since a slight gap exists between the convex portion and the concave portion, the two housing members are deviated and moved, and the positioning precision is deteriorated in some cases. In order to eliminate the gap to enhance the positioning precision, it is necessary to form the convex portion and the concave portion with high fitting precision, and labor is required for producing the housing members.